The International Federation of Red Cross and Red Crescent Societies welcomed the move.

"While it does not change the reality on the ground for victims or partners engaged in the response, we hope it will bring the international attention that this crisis deserves," it said in a statement.

How bad is the situation in DR Congo?

The outbreak, the second largest in history, started in August 2018 and is affecting two provinces in DR Congo - North Kivu and Ituri.

More than 2,500 people have been infected and two-thirds of them have died.

It took 224 days for the number of cases to reach 1,000, but just a further 71 days to reach 2,000.

About 12 new cases are being reported every day.

Isn't there a vaccine?

Yes.

It is 99% effective and more than 161,000 people have been given it.

However, everybody is not vaccinated - only those who come into direct contact with an Ebola patient, and people who come into contact with them.

The vaccine was developed during the epidemic in West Africa and has been available throughout the latest outbreak.

Why hasn't the outbreak been brought under control?

Tackling the disease has been complicated by conflict in the region.

Since January, there have been 198 attacks against healthcare workers or Ebola treatment facilities leading to seven deaths and 58 injuries.

Another major problem has been distrust of healthcare workers leading to about a third of deaths being in the community rather than at a specialist Ebola treatment centre.

It means those people are not seeking treatment and risk spreading the disease to neighbours and relatives.

Media playback is unsupported on your device

Media captionTreating Ebola in the DR Congo warzone

There has also been difficulty tracking the spread of the virus.

A significant number of cases are coming as a surprise as those affected have not come into contact with known Ebola cases.

"We are one year into the outbreak and the situation is not getting any better," said Trish Newport, from the charity MSF.

"It's a complex environment with a long history of violence, of conflict, so there's a lot of mistrust of foreigners from outside the area.

"We have to build ties and connections with the community so they trust us."